Three cheers for the Hi-Tec-C Coleto! This device takes the all-time favorite, the Pilot Hi-Tec-C, and makes it into a multi pen! Now you can pop in any color cartridges of your choice and customize your own unique multi-pen. Cartridges come in 0.3mm, 0.4mm and 0.5 mm sizes.

Great cartridge, ink color as described. Only issue is that sometimes the ink
doesn't flow immediately. In my experience this is consistent across all of the
Coleto line inks and sizes. Would recommend.